Slipped upper femoral epiphysis

Question 1

What is slipper upper femoral epiphysis?

Answer 1

Occurs when weakness in the proximal femoral growth plate allows displacement of the epiphysis of the femoral head postero-inferiorly

Question 2

What is the pathophysiology of SUFE?

Answer 2

In slipped capital femoral epiphysis, the perichondrial ring becomes too weak to
resist the shearing forces between the femoral head and neck causing the two
gradually slip away from each other

Question 3

How do bones grow normally?

Answer 3

o Normally femur consists of 4 parts
▪ Diaphysis (shaft of the bone)
▪ Metaphysis
▪ Neck
▪ Physis/growth plate: contains cell which divide and allow bone to grow in
length → growth plate eventually ossifies and fuses with the epiphysis (~age
16 in females and age 19 in males)
o During growth spurt, the growth plate is relatively weak and vulnerable to shearing
forces
o Before the growth plate ossifies, it is supported by the perichondrial ring (dense
connective tissue that extends from the metaphysis to the epiphysis). The
perichondrial ring helps resist shearing forces so that the femoral head and femoral
neck don’t slip away from one another

Question 4

Whys if SUFE bad?

Answer 4

o It is not actually the epiphysis that slips away → it is the neck that displaces
anterolaterally and superiorly
o If the displacement is severe, it can tear the epiphyseal blood vessels interrupting the
blood supply to the femoral head. If this happens, it can lead to avascular necrosis of
the femoral head

Question 5

Who gets SUFE?

Answer 5

Obese boys aged 10-15 years during growth spurt

Endocrine abnormalities and FHx are also risks

Question 6

What are the clinical features of SUFE?

Answer 6

• May present acutely following trauma or more commonly with chronic, persistent symptoms
• Acute (after minor trauma) or insidious onset of pain and limp
• Bilateral in 20%
• Hip, groin, medial thigh or knee pain
• Examination shows restricted abduction and internal rotation of the hip

Question 7

What investigations do you do for SUFE?

Answer 7

X-ray including frog lateral view
o Bilateral AP X-ray will show Klein’s line, which is drawn along the superior aspect
of the femoral neck, not intersecting the femoral head (normally intersects some part
of the femoral head)
o Frog-leg lateral X-ray will show Bloomberg’s sign (physis will be blurred or
widened), widened joint space and displaced femoral head

Question 8

What is the management for SUFE?

Answer 8

• Surgery: pin fixation in situ → screw fixed through growth plate to the femoral head to
stabilise the femoral head
• Period of rest with limited weight bearing